Table 2. Univariate and multivariate cox regression analyses of factors affecting overall patient survival.

Variable	Univariate				Multivariate
	P	HR	95% CI		P	HR	95% CI
Chemotherapy	0.29	1.239	0.835, 1.838		0.20	1.368	0.848, 2.204
Gender, vs. female
Male	0.54	1.13	0.763, 1.673		0.90	1.031	0.630, 1.687
Age (years)
≤50	0.02				0.03
51–74	0.03	2.277	1.095, 4.736		0.01	2.974	1.243, 7.118
≥75	0.006	3.366	1.415, 8.005		0.009	4.097	1.411, 11.892
Race
White	0.48
Black	0.99	0.997	0.538, 1.85
Hispanic	0.59	0.866	0.512, 1.463
Asian	0.13	0.685	0.423, 1.11
Marriage
Unmarried	0.22
Married	0.56	1.187	0.672, 2.097
Divorced/separated/widowed	0.11	1.755	0.879, 3.501
T stage
T1	<0.001				0.001
T2	0.001	2.236	1.375, 3.635		0.010	1.972	1.179, 3.297
T3	<0.001	3.563	2.036, 6.234		0.001	3.010	1.586, 5.713
T4	<0.001	3.662	1.871, 7.168		0.001	3.628	1.659, 7.934
N stage, vs. N0
N1	0.02	2.25	1.127, 4.489		0.18	1.784	0.772, 4.120
M stage, vs. M0
M1	0.059	2.115	0.971, 4.606		0.94	1.041	0.386, 2.808
Household income (dollar)
<55,000	0.46
55,000–75,000	0.65	0.881	0.513, 1.513
>75,000	0.26	0.733	0.426, 1.259
Radiotherapy	0.18	0.047	0.001, 4.119		0.97	<0.001	<0.001, >999

CI, confidence interval; HR, hazard ratio; M, metastasis; N, node; T, tumor.